Recuperative soaking pit



v Sept.` 30, 1930. G. R. McDl-:RMOTT 1,777,125

RECUPERATIVE soAKING PIT Filed April 4, 1928 l NVENTOR ATTORNEYS atentedv Sept. 30, 1930 NITED STATES GEORGE R. HCDERMOTT, OF MOUNT VERNON, OHIO, ASSIGNOB TO THE CHAPMAN-STM FUBNACE COMPANY, OF MOUNT VERNON, OHIO, A CORPORATION OF OHIO BECUPERATIVE SOAKING :PIT

Application led April 4, 1928. Serial No. 267,238.

The inventionA relates to soaking pits, more particularly of the type wherein the air for combustion is preheated by passing it through a recuperator heated by the waste gases exhausted from the pit, and the primary object of the invention is to provide a distribution of the heating ases in the soaking pit which will secure uni orm heating conditions there- 1n.

Further objects and advantages of the invention will bev in part obvious and in part specifically referred to in the description hereinafter contained, which, taken in conjunction with the accompanying drawings, discloses a preferred embodiment thereof such embodiment, however, is to be considere merely as illustrative of its principles. In the drawings- Fig. l is a vertical section through a furnace constructed in accordance with the invention, and

Fig. 2 is a transverse section taken on line A, B, C, D, and E of Fig. 1. v

In the illustrated form of the invention I have shown a soaking pit`1 having a removable cover 2 and a bottom 3, adapted to receive ingots 4 in the usual manner. The air and gas for combustion come in respectively through -soaking pit and across the to s of the ingots one or more air conduits 5 and gas conduits 6, which latter mix the gas with the air prior to their entry into the soaking pit, the combustible mixture being admitted into the soaking pit at the upper part of' one of its sidewalls in such manner that the gases of combustion first pass across the pit over the tops of the ingots and then turn downwardly as indicated by the arrows in the drawing, and a portion of such gases return in a horseshoe shaped path, until they pass out of the pit through one or more exhaust passages 7 located at the bottom of the same sidewall.

The exhaust gases then pass through a suit-V able heat interchanger or recuperator 8, the illustrated construction Y being substantially as shown in the U. S. patent to Stein No. 1,404,721, January 24, 1922, in which type of recuperator the wastel gases pass in a zig-zag ath through the recuperator from top to ottom and are finally led into a collecting flue 9 controlled by a dam er 10, and communicatin with the stack ue 11.

The air or combustion passes up vertically through a recuperator of the above type to a gathering chamber 12 located at the top of the recuperator and communicating with the air conduits 5 above mentioned.

In accordance with the present invention a portion of the heating gases is led through the soaking pit 1 in a horseshoe path and exhausted through passages 7 as above described, and another portion of the heating gases is diverted therefrom by means of one or more exhaust ports 13, preferably located near the bottom of the` 1t, and in or near the sidewall thereof whic is opposite to the sidewall in which the above mentioned ex.- haust passages 7 are located. In the illustrated form of the invention auxiliary exhaust ports 13 are located on opposite sides of a door -14 in the front wall of the furnace, and further auxiliary exhaust ports 15 are also provided in the opposite sidewalls of the pit near its front corners, the exhaust ports 13 and 1'5 above mentioned communieating with exhaust gas conduits 16 running through the sidewalls of the soaking pit.

The heating gases thus will pass into the arrangement of points and exhaust "passagesabove described, the gases are exhausted at or near the four corners of the soaking pit.

As above stated, the exhaust gases passing out through passages 7 preferably are led through the recuperator 8, to which the conduits 16 also may be connected. l prefer to connect the conduits 16 .to the recuperator at points where the suction is somewhat greater as compared to the point of entry of the gases issuing Vfrom ports 7. In the illustrated form of the invention the exhaust gases Vcoming into the' recuperator from passages 7 make three horizontal passes across the recuperatr at different levels, and the conduits 16 l Yfor admitting a combustiblermixture, at one enter the recuperator at the chamber 17, which is'interposed between the second and third passes, and subjects the conduits 16 to a somewhat greater suction. The major portion of the spent heating gases however, usually will pass out of the soaking pit through passages The proportion of flow of spent gases through the above paths may be regulatedby means of dampers 18 (Figi. 2) associated with conduitsl, and'further'dampers "19 (Fig. 1) controlling the iow through the l'recuperator of the gases passing out of the Vpit through passages 7.

While a speciicembodiment ofthe inventionhas been disclosed, it is obvious thatVY many chan es may be made therein Without departing rom its principles as set forth in the appended claims. l

I claim:

1. In combination, a soaking pit, means for admitting a combustible mixture at one side:YY thereof .and projecting the resulting gaseous stream across the'soaking pit to the opposite side thereof, said pit having one or more exhaust passages' for the heating gases near the same side thereof which cause i a portion of said stream to return across the Ypit in a horseshoe sha ed path and pass out of the pit through sai passages, and one or more auxiliary'exhaust ports located adjacent the op @site side of the pit which divert a portion o? said gaseous stream from said horseshoe shaped ath.

2. In com ination, a'soaking pit, means for admitting a combustible mixture at one side near the top of the pit and projecting the resulting gaseous stream across the soaking pit to the opposite side thereof, saidpit having one *or moreY exhaust passages for the heating gases near the same side and near the bottom of the pit which cause a portion of said stream to return across the pit in a horseshoe shaped path andlpass out of the pit through said passages, and one or more auxiliary exhaust ports located near the 0pposite side of the pit which divert a portion of said gaseous stream from said horseshoe shaped path and near the bottom thereof.

n3. In combination, a soaking pit, means for admitting apombustible mixture at one side thereof and projecting the resulting gaseous stream across the soaking pit te the opposite side thereof, said pit having one or more exhaust passages for the heating gases near the saine side thereof which cause a portion`of said stream to return acrossYV the pit in a horseshoe sha ed path and pass out of the pit through sai passages, one or more auxillary exhaust Vports located adjacent the opposite side of the pit which divert a portion of said gaseous stream from saidV horseshoe shaped path,YV and a heat interchanger receiv- 1ng the gases Vexhausted both fromlsaid passages and said portsf c 4. In combination, a soaking pit, means tion of said stream to return across the pit in a horseshoeshaped path and pass out of the pit through said passages, one or more auxiliary exhaust ports located adjacent the opposite side of the pit which divert a portion of said gaseous stream from said'horseshoe shaped ath, and means for regulating the proportion of gases owing through said passages 'and ports. i

5. In combination', a soaking pit, means for admitting'a combustible mixtiire at one side thereof, said pit having one or more exhaust passages for the heating gases nearVY the sameV side thereof, one or more auxiliary exhaust ports located adjacent the opposite sir-de of the pit, a heat interchan er f the suction type connected both to sai passages yand said ports, the ports being connected to 9- the heat interchanger at a point where the suction is greaterthan with respect to the passages. i i l 6. In combination, a soakin pit, means f or admitting a combustible mixture at one side thereof, said pit having one or more exhaust passages for the heating gases near the same side thereof, one or more auxiliarv exhaust ports located adjacent the opposite side of the pit, arecuperator of the suction type wherein the heatin gases pass through i from top to bottom, sai passages leading to theupper part of the recuperator, and conduits 'connecting said auxiliary ports to a point-1n said recuperator at a lower level.

'In combination, a heat interchanger, a soaking pit, means forfadmitting a combustible mixture thereto at the top of the pit, said pitihaving one or 'more exhaust passa es for the 'heatingrgases located near the ttom` 115 of the pit at one end thereof and which are connected to said heat interchanger to pass a portion of the heating gases therethrough, and means for withdrawing another portion of the vheating gases from one or more points 120 near the bottom of said pit at the opposite end thereof and by-'passing the same around a which [cause a ortion of said stream to return in a horses 'oe shaped path and pass out of the pit through said passages, and said pit also havin auxiliary exhaust ports 1op cated near the ottoms of the corners at the opposite side of the, pit which divert a port1on'of said gaseous stream from said horseshoe shaped path.

'In testlmony that I claim the foregoing, I 10 have hereunto set my hand this 28th day of March, 1928.

GEORGE R. MCDERMOTT. 

